Two cycle internal combustion engine



July 28, 1931.

H. ANDRESEN TWO-CYCLE INTERNAL COMBUSTION ENGINE Filed Oct. 16, 1929 2Sheets-Sheet 2 Patented July 28, 1931 sens 1 mnnes m YANQQW 331N 1-GO'L'FMBLA, elret c e 'rwo QYGLE INTERNAL COMBUSTION" ENGINE Applicationfiled October 16, 1929. Serial No. 400,017,

This invention relates to improvementsjn internal combustion engines,ndamcre p ticularlydtQ these commo y known .esth wel ycletype. Itispeculii ly we ladepted 5 for-use in connectionith aeroplane engines,

but; is 511013. limited thereto- I vlhe improvements: are; mainlycncerned with :efficient heat rad ation, e e tive y m: der: scavenging,increased compressien, I reduetiondof moving. perts,;and a generalfreedone from ;CQmp16X ftyab0th as rega d Ina,- ohining Land assemblageas eomparedrwi'th engines'of the same type now. in ogue.

t Theengine consists of a plurali y fizmain 16 cylinders each closed atone enol by aspark plug and at the other end :by a,flange-member',secu.red thereto and-carrying 0ni s inn faee a tubularpr'ojectienextending appra mately midway of thema in ;.cy linder,, and

we thcre term nating n a piston e th surface'of: the latter isthe'orifice of ejlongitndinel passage, which, at its otherend registers;with a; ,correspondingpassage in 5 the flange, and thereby connects witha longitu- 5 dinalpassage on the exteri r. of t e mai cylinder, leadingo c mb r c1e$e *by;.e automatic alve. Armovable sleeve of the u e 0i e ps on eylinderreciprocates lo it dinally between the inner Wall of the;main cylinder and the exterior of the piston head of the fixed tubular;projec io a d is conne ted tot-h wrist pin of weonnecting-rod int-heusual Way.

By this arrangement and. ,d p sitione th pants e eh rge 0f ee bustbleimix urem ybe drawn-into the movable ylinden and co Pressed again thefi pi t n-heed hi the tubular p oj ction, enc p ss ng th ough theongitud n pa sage t ere o ;b6-'; dmitted by way of t e au om t c lve vet0 th main cylinder and there tobe further compressed by the piston-headofthe. reciprOQaJting piston-cylinder. On the completion of theexplosion stroke which immedietely follows there is a Very effectivescavenging operation, which is a salient feature ofit-heinvention, Thisis --brough-t about by a; specially fl-ared nozzle intake by-which apowerful and converging fl w o ai dire rei grh a po t th m ab e pistonin ;a ir t on Ene Inel t9 he ,cylinclee end, mhexeby the by=p ie4luetspfieembu tionhre rie enmi i theykih- Cle th eug e we ltoport, amtso-lhevii g e Ilinder h rged l with: if es l stea egy-produets;theeycleis.theerepeet,

ed, as described. i 4 i The. invention is-Jnore cleerly tdeserihed the.-aid.1 :f vt e d i ngs ee empenyine ed for ing a perte this, eppl i' eten iendo-in which; Figure 1,-is e geh r l lepgitu ine sseetion sh vy ngthe rela ion oith'e par-t eceneemed- F gu e 2 i a. s milar i w ethat ofF g r bet exie lyr ghtrangelar thereto, F gure .3 is e viewpfthe fixedpiston. t F g re 4 is simil mie but exiellyr gbt angu-lerte het of Fgures. v F gu e .5isan eleietionalv ew ctrhe newable piston, pertly isectie I ln these d awingsthe numer l 16 indieates -79 the hored po ti no the mein cylinde iefithe engme, f -hlCh .7 s th emerged exter ien n eg ged by the ringoi th Pi$ QI .-8,- Th m m eyhnder has c esed'enrds; theead e d 91havi g ve screwrthreaded.seet iorthe +59 Spa plug 1 hi e the.eth r .ie dis pr videdawi tl aia-eed flange ,11. to receiveth ylmd h-e rr ;l.2, e, hrough wh ch the Leonhe ting 11 d 13 passe an i n ich gaspassage 1;; is'f rmed. 4W Integral with th cover 121s the tubular pr lctlen 1 w ich is divi ee entrally let l fitoele r th w ecti gmdjm,andsis p 'Yided w th a zpistonhea 7, vim thei e 'Q whip}; is theogrifice 142,955 the gas ,,pes sage 14, A sleeyemember;l8-,of the nature,ofi l nga ed ubu es pistem made truly seyi'iin- .d ie e inside and. eusid (reeip eeet s ngi u in lly be we n; he nne endseute wallsrespectively of thew-main .oy.l;i n d er L6,, and theepiston heaclglfiofthe tubular-(prof jeetion 15 whereby a doubleieompressioe eat.- feet. is ured. 'Wimina h pis es-heed; 8 at 19.,andthe other-outside feat 20.Thesleeye= 1 member 18 is secured tothe wrist gin 21 and connected inthe-usual- Way. ;The main-8X- h us pessa geis at 22, e z d he ntakefrom. the carhureter or itsequivalentis at hi e eppeeit on th wa l: eatthe whim we cylinder 6 are ports or passages at 24 and 25. The former ofthese connects with the top chamber of the spring controlled valve 26,while the underside of the valve connects with the gas passage 1%, andthe latter pas sage 25 externally flared to receive and converge the airstream due to the relative velocity of the vehicle. The sleeve-member 18is provided with a lateral port 27 for the intake of combustible mixtureto the compression space 19, and on its opposite wall has an air port28, which connects the convergent pi re with the compression space 20 inthe cylinder 6. i

The functional operation of the device may be briefly summarized asfollows Assuming that the cycle commences with the piston-cylinder atthe inward end of its stroke as the latter takes its outward stroke avacuum is produced within it until the wall port 27 registers with theintake port 23 in the main cylinder. This fills the interior of thepiston-cylinder 18 with combustible mixture which is graduallycompressed by the if following flrd stroke, and thereby driven throughthe gas passage 14 in the projecting member 15, thence into the externalpassage 29. andv into the gas compres ion chamber 30.

The piston cylinder has now reached the limit of its inward stroke, thesecondary gas passage has been closed by the piston of the pistoncylinder, and has caused the port 28 in the head of the piston cylinderto register with the air port 25. It has also fully uncovered theexhaust port 22 by which a rush of fresh air enters the head end of themain cylinder, and escapes by the exhaust port leaving the cylinder fullof fresh air. It should be understood that in use on airplanes or motorcars for which this invention has been especially designed, the passageof scavenging air into the cylinder is governed bv the forward motion ofthe vehicle, and in cases where the engine is used in airplanes. the airis forced into the cylinders through the passages 25 28 when they are inregister due to the forward motion of the airplane. and also thebackward draft from the airplane propeller: when used as a stationaryengine a blower will be attached to the port to force air in.

The piston cylinder now commences its o tward stroke. therebyimmediately blocking the air port 25 and the exhaust port 2.2 in the man cvlinder and causing the port 28 in the head of the piston cylinder torep;- ister with the secondary gas port 24 leading to the top of thespring controlled valve 26. The initial charge of the combustiblemixture, which was compressed by the piston cylinder, has now freepassage to the compression space in the head end of the main cylinder 6by way of the spring controlled valve 26, which it raises from its seat.This additional charge is added to the slightly compressed fresh air inthe main cylinder and is compressed by the further progress of thepiston cylinder until explosion point reached. The explosion completesthe inward stroke until the secondary gas port- 2-l registers with theport 28 of the piston cylinder, but by the action of the valve 26 noproducts of combustion are admitted to the gas chamber 80, the secondarygas port being thereafter immediately closed and the exhaust port 22opened for the discharge of the combustion by-products, and the ingressof the fresh air stream thus completing the cycle.

I claim:

1. In a two cycle internal combustion engine, a main cylinder having aclosed head and a working chamber, a piston-cylinder working within saidmain cylinder, a fixed piston within said piston-cylinder, said maincylinder having a piston controlled inlet port for the explosive mixtureto the working chamber and having an exhaust port from the workingchamber, said fixed piston and said main cylinder having a ductcommunicating at its receiving end with the space between the heads ofsaid fixed piston and said piston cylinder and communicating at itsoutlet end with said inlet port of the working chamber, a back checkvalve in said duct, said main cylinder having a charging port out ofdirect communication with the working chamher, said piston-cylinderhaving a port controlling the passage of a charge from said chargingport to the space between the heads of said fixed piston and saidpiston-cylinder, said main cylinder having a scavenging air inlet portcontrolled by the piston-cylinder to admit air into the working chamberat the end of the working stroke, said scavenging air inlet port beinglocated at that portion of the cylinder facing the direction of movementof the vehicle on which the engine may be mounted and having a flaredmonth, said ports and said ducts being so positioned with respect to oneanother that the piston-cylinder will on its inward stroke first coversaid charging port, then uncover said inlet port, then uncover saidexhaust port and effect communication between said scavenging inlet portand the working chamber, said pistoncylinder on its return or outwardstroke first reclosing said exhaust port and said scavenging port andthen effecting communication between said inlet and the interior of theworking chamber and finally effecting communication between saidcharging port and the space between the heads of said fixed piston andsaid piston-cylinder.

2. In a two-cycle internal combustion engine, a main cylinder having aclosed head and a working chamber, a piston-cylinder working within saidmain cylinder, a fixed piston within said piston-cylinder, said maincylinder having a piston controlled inlet and a piston controlledexhaust port for the working chamber, said fixed piston and said maincylinder having a duct communicating at its receiving end with the spacebetween the heads of said fixed piston and said pistoncylinder andcommunicating at its outlet end with said inlet port of the workingchamber, a back check valve in said duct, said main cylinder having acharging port located out of direct communication with the workingchamber, said piston-cylinder having a port controlling the passage of acharge from said charging port to the space between the heads of saidfixed piston and said piston-cylinder and having a duct for passing acharge from said inlet port into the working chamber, said ports andsaid ducts-being so positioned with respect to each other that saidpiston-cylinder will, on its inward stroke, effect an opening of saidexhaust port while maintaining said inlet port closed and then on itsoutward stroke cover said exhaust port and open said inlet port to theworking chamber and subsequently close said inlet port and opencommunication between said charging port'and the space between the headsof said fixedpiston and said piston-cylinder.

3. In a two-cycle internal combustion engine, a main cylinder having aclosed head and a working chamber, a piston-cylinder working within saidmain cylinder, a fixed piston within said piston-cylinder, said maincylinder having a piston controlled inlet port and a piston controlledexhaust port for the working chamber, said fixed piston and said maincylinder having a duct communicating at its receiving end with the spacebetween the heads'of said fixed piston and said pistoncylinder andcommunicating at its outlet end with said inlet port of the workingchamber, a back check valve in said duct, said main cylinder having acharging port located out of direct communication with the workingchamber, said piston-cylinder having a port controlling the passage of acharge from said charging port to the space between the heads of saidfixed piston and said piston-cylinder and having a duct for passing acharge from said inlet port into the working; chamber, said ports andsaid ducts being so positioned with respect to each other that saidpiston-cylinder will, on its inward stroke, effect an opening of saidexhaust port while maintaining said inlet port closed and then on itsoutward stroke cover said exhaust port and open said inlet port to theworking chamber and subsequently close said inlet port and opencommunication between said charging port and the space between the headsof said fixed piston and said piston-cylinder, said main cylinder havinga scavenging air admitting port located below saidinlet port and saidsecond mentioned piston-cylinder duct serving to efiect communicationbetween said scavengport ,ing air admitting port and the working chamberwhen said piston-cylinder is at the limit of its inward stroke for thepurposes specified. In testimony whereof I have hereunto af fixed mysignature.

Vancouver, British Columbia, Canada.

HANS ANDRESEN.

